This invention concerns use of 9-cyclohexyl-9H-adenine or 9-benzyl-2-n-propoxy-9H-adenine in a bronchodilating process. Compounds of the instant process have non-adrenergic smooth muscle relaxant properties and are particularly valuable in overcoming acute bronchospasm and as adjuncts in symptomatic management of chronic, obstructive pulmonary diseases (e.g., asthma, bronchitis, emphysema).
Regarding types of non-adrenergic bronchodilators, the theophylline group of xanthine derivatives are particularly prominent. For instance, aminophylline, the ethylenediamine salt of theophylline, is an effective bronchodilator which may be administered parenterally, orally, or rectally and is useful in patients where direct relaxation of bronchial muscle is desired. Notwithstanding widespread use, the xanthine class of non-adrenergic bronchodilators have major disadvantages with respect to gastric irritation, cardiovascular and central nervous system side effects. Thus, there is a need for new and effective bronchodilators with increased potency and/or fewer or reduced untoward effects. Compounds employed in the instant process have been shown by standard pharmacological tests to be effective non-adrenergic bronchodilating agents with minimal cardiovascular and central nervous system effects.
Regarding prior art, 9-cyclohexyl-9H-adenine has been synthesized for use as a possible anticancer agent. It has also been tested as an anti-inflammatory and found to have no activity or activity of no practical value. As for 9-benzyl-2-n-propoxy-9H-adenine, this compound is believed to be novel although the corresponding "2-methoxy and 2-ethoxy" homologs reportedly have anti-inflammatory properties. The above prior art teachings are disclosed in the following references.
1. U.S. Pat. No. 3,930,005 (Wojnar, et al.) generically discloses inter alia compounds of the formula ##STR1## wherein R is (lower)alkoxy (e.g. specifically methoxy and ethoxy but no propoxy). The compounds are said to possess anti-inflammatory properties.
2. J. A. Montgomery, et al., J. Am. Chem. Soc., 80, 409-411 (1958) describes synthesis of the compound ##STR2## as a potential anti-cancer agent. The Wojnar, et al., patent supra teaches that the compound is relatively inactive as an anti-inflammatory agent.
3. U.S. Pat. No. 3,862,189 (Schwender) concerns compounds of the formula ##STR3## wherein, inter alia, R.sub.1 is amino, alkylamino, aralkylamino, etc.; and R.sub.2 is di-substituted phenylalkyl, tetrahydroquinoylalkyl, etc. reportedly useful as antianginal or bronchodilator agents.